The present invention relates generally to laser processing of integrated circuits on semiconductor wafers, and relates in particular to severing conductive links (e.g., link blowing) on memory integrated circuits. For example, “LIA Handbook of Laser Materials Processing,” by J. F. Ready, Laser Institute of America, 2001, discloses general information regarding link blowing at Chapter 19.
When manufactured, memory die typically include some number of defective memory cells due to limitations in semiconductor fabrication technologies. To make memory die with defective memory cells useable, memory die are typically manufactured containing extra memory cells that may be used in place of defective cells. The defective memory cells must then be isolated. Integrated circuit memory repair systems employ a focused laser beam to open (or blast) fusible links on integrated circuit memory die in order to provide that only properly functioning memory cells are coupled to the circuit memory.
The processing speed of conventional memory repair systems, however, may be limited by the pulse repetition rate of the laser system. As the demands of laser processing systems increase, there is a need for memory repair systems to be faster and more efficient. Efforts to change the pulse rate however, for example by increasing the Q switch rate, result in changes in pulse shape and energy, which may adversely affect memory system repair.
There is a need, therefore, for faster and more efficient memory repair systems.